Preparation of a polyurethane electret nanofiber membrane and its air-filtration performance.

Pollution by atmospheric particulate matter (PM) is a serious threat to human health, and traditional window screens are unable to intercept fine particles. Therefore, it is urgent to develop anti-haze window screens to effectively protect the public. We prepared a polyurethane/silicon nitride (PU/Si3N4) electret nanofiber membrane with a minimum diameter (350 nm) and narrower diameter distribution than those of PU-Boehmite, PU-SiO2, and PU-TiO2 membranes by electrospinning. The PU-Si3N4 fiber membrane has good mechanical properties with stress of 18.05 MPa and strain of 170%. Moreover, PU/Si3N4 exhibits a maximum current peak (2.63 pA) at 90 °C. Importantly, PU/Si3N4 membranes applied to window screens still maintain high filtration efficiency (79.36%) and low resistance (25 Pa) to air flow at a low areal density of 1.22 g/m2. Furthermore, they show good light transmittance (40%) and air permeability (46.42 mm s-1). Therefore, PU/Si3N4 electret nanofiber window screens have broad application prospects.